It especially has Raphael, "one of the seven angels who enter and serve before the Glory of the Lord." Included in his service was the task of reading the prayers of both Tobit (blinded and mocked) and Sarah (widowed and mocked).
So Raphael was sent to heal them both: to remove the cataracts from Tobit's eyes, so that he might again see God's sunlight; and to marry Raguel's daughter Sarah to Tobit's son Tobiah, and then drive the wicked demon Asmodeus from her.
Now, what you'd want, or at least what I'd want, is for Raphael to appear before Tobit and say, "The LORD has heard your prayer, your eyes are healed," then turn to Tobiah and say, "I will transport you instantly to Media, where you will marry Sarah once I drive the demon away."
But that, of course, isn't God's way. Even when He is as unsubtle as sending an archangel in the form of a man to answer a prayer, He does it such that the cooperation of the person whose prayers are being answered is required. This way, the person's free will is preserved, and consequently the very process of having his prayer answered is a source of virtue and an opportunity to grow in holiness.
When you think about it, if Tobit, who in his own words "walked all the days of my life on the paths of truth and righteousness," suddenly found an angel of the LORD appearing before him to heal him, he may well backslide from righteousness into childish presumption. "It is better for me to die than to live, because I have this crick in my neck, and I am overwhelmed with grief... I said, I have this crick in my neck... So where's the angel already?"
There's a lesson in that, I suppose, although those of us who are currently childishly presumptuous might be willing to put off learning it until tomorrow.